• 제목/요약/키워드: B/A Ratio

검색결과 7,143건 처리시간 0.036초

Greening에 따른 유채 자엽의 엽록소-단백질 복합체 형성 (Formation of Chlorophyll-Protein Complexes in Greening Rape Cotyledons)

  • 이진범
    • Journal of Plant Biology
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    • 제26권2호
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    • pp.91-99
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    • 1983
  • The formation of chlorophyll-protein complexes (CP-complexes) during the greening of rape cotyledons (Brassica napus cv. Yongdang) was investigated by the SDS-polyacrylamide gel electrophoresis. The total chlorophyll content and Chl a/b ratio were also determined. In addition, the effects of dark treatment on the CP-complex patterns during greening have been examined with respect to their photosynthetic electron transport activity. Greening has brought about the increasein total chlorophyll content and the decrease in Chl a/b ratio, but there have been no changes in Chl a/b ratio after 24 hrs of greening. The light-harvesting chlorophyll a/b-protein complex (LHCP-complex0 was predominant during the initial greening period. Thereafter, the amout of chlorophyll a-protein complex (CP I-complex) was gradually increased. Twenty-four-hr dark treatment immediately after illumination for 6 hrs and 12 hrs resulted in the increase of the Chl a/b ration and the CP I complex, otherwise the decrease of the LHCP-complex. The LHCP/CP I ratio was gradually decreased with further greening, and appeared no change after 48 hrs illumination. The investigation of the photosynthetic electron transport activity indicated that photosystem (PS) II activity (H2Olongrightarrowp-PD*+FeCy**) did not change, but the activity of PS I was increased suddenly due to the dark treatment. The data suggests that the increase of CP I-complex may result in that of P-700, that is, the increase of PS I activity.

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확산법에 의한 Bi-2223 초전도상의 제조 및 성장기구에 관한 연구 (Study on the fabrication and the growth mechanism of Bi-2223 superconducting phase by diffusion method)

  • 최성환;최효상;한태희;황종선;한병성
    • E2M - 전기 전자와 첨단 소재
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    • 제7권4호
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    • pp.281-288
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    • 1994
  • According to spread volume of B(BiPbCuO) layer, composition ratio and each stage of sintering process, we studied stability of high Tc superconductor phase and generation and growth movement of superconducting phase. The dual layer composed of SrCaCuO and BiPbCuO compound were prepared to develop the Bi-2223 superconductor[108K] through interaction and diffusion during sintering process. The dual layer samples were sintered at 830.deg. C for 0-210 hours. From the result, the optimum conditions were : spread volume(A:B=1:0.6), sintering time(210h) and composition ratio(A:S $r_{2}$C $a_{2}$C $u_{2}$- $O_{x}$, B:B $i_{1.9}$P $b_{0.5}$C $u_{3}$ $O_{y}$) at 830.deg. C.. C.C.C.

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소광비, 처핑 및 자기위상변조가 2.5Gbit/s 직접변조한 DFB-LD의 전송성능에 미치는 영향 (The effect of extinction ratio, chirp and SPM on transmission performance of directly modulated 2.5 Gbit/s transmitter)

  • 김근영;이용기
    • 한국광학회지
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    • 제12권3호
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    • pp.212-218
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    • 2001
  • 직접변조한 2.5Gbit/s 송신기에 있어서 DFB-LD에 인가되는 바이어스 전류에 따른 출력 광신호의 소광비와 처핑의 관계를 살펴보았고, 이상분산 영역 전송실험을 통행 변조된 광신호가 8-10dB의 소광비를 가질경우(바이어스 전류가 발진임계전류의 1.5배에서 1.8배) 소광비와 처핑으로 인한 총 전송 패널티가 최소가 됨을 알 수 있었다. 또한 240km 이상분산 영역 전송실험을 통해 직접변조된 광신호의 소광비와 SPM의 상관관계도 분석하였다. SPM을 고려할 경우 본 실험과 같은 구성에서 전송거리가 200km 미만인 경우는 10.2dB의 소광비에서 200km 이상인 경우는 8.4dB의 소광비에서 가장 좋은 수신감도를 얻을 수 있었다.

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Pull-Out Behaviour of Hooked End Steel Fibres Embedded in Ultra-high Performance Mortar with Various W/B Ratios

  • Abdallah, Sadoon;Fan, Mizi;Zhou, Xiangming
    • International Journal of Concrete Structures and Materials
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    • 제11권2호
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    • pp.301-313
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    • 2017
  • This paper presents the fibre-matrix interfacial properties of hooked end steel fibres embedded in ultra-high performance mortars with various water/binder (W/B) ratios. The principle objective was to improve bond behaviour in terms of bond strength by reducing the (W/B) ratio to a minimum. Results show that a decrease in W/B ratio has a significant effect on the bond-slip behaviour of both types of 3D fibres, especially when the W/B ratio was reduced from 0.25 to 0.15. Furthermore, the optimization in maximizing pullout load and total pullout work is found to be more prominent for the 3D fibres with a larger diameter than for fibres with a smaller diameter. On the contrary, increasing the embedded length of the 3D fibres did not result in an improvement on the maximum pullout load, but increase in the total pullout work.

배경음악 분리를 위한 확장된 합성곱을 이용한 멀티 밴드 멀티 스케일 DenseNet (Multi-band multi-scale DenseNet with dilated convolution for background music separation)

  • 허운행;김혜미;권오욱
    • 한국음향학회지
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    • 제38권6호
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    • pp.697-702
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    • 2019
  • 방송 콘텐츠의 혼합 신호에서 배경음악 신호를 분리하는 확장된 합성곱을 이용한 멀티 밴드 멀티 스케일 DenseNet을 제안한다. 확장된 합성곱은 스펙트로그램의 다양한 스케일 문맥 정보를 학습하기 용이하도록 한다. 컴퓨터 모의실험 결과, 제안한 구조는 신호대잡음비(Signal to Noise Ratio, SNR) 0 dB, -10 dB의 환경에서 각각 0.15 dB, 0.27 dB의 신호대왜곡비(Signal to Distortion Ratio, SDR)를 개선하였다.

유기전압비를 이용한 변압기 보호계전 알고리즘 (A Transformer Protective Relaying Algorithm Using the Ratio of Induced Voltages)

  • 강용철;이병은
    • 대한전기학회논문지:전력기술부문A
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    • 제49권10호
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    • pp.524-530
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    • 2000
  • This paper presents a transformer protective relaying algorithm using the ratio of induced voltages. The proposed algorithm calculates primary and secondary voltage from currents and voltages of primary and secondary windings. The ratio of primary and secondary induced voltages is equal to the turn ratio in case of the steady state and magnetic inrush. On the other hand, the ratio is different form the turn ratio in case of internal winding faults. The algorithm does not require B-H curve and can reduce the relay's operating time.

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MLS$_B$계 항생물질 유도 내성 세균에서 In vitro로 선발된 지속성 내성형 erm(A)와 erm(C)의 분자적 특성 규명 (Molecular Analysis of Spontaneous Mutations in erm(A) and erm(C) Selected In vitro as a Constitutive MLS$_B$ Resistant Staphylococci)

  • 윤은정;진성혜;최응칠;심미자
    • 약학회지
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    • 제51권2호
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    • pp.108-114
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    • 2007
  • The predominant Macrolides-Lincosamide-Streptogramin B (MLS$_B$) antibiotics resistance genes in staphylococci are erm(A) and erm(C). There is the phenomenon that the ratio of constitutively MLS$_B$ antibiotics resistance (cMLS) in erm(A) is much higher than in erm(C). Thus, we confirmed that the difference of the mutation ratio between erm(A) and erm(C) makes the phenomenon. We examined 8 staphylococci carrying inducibly expressed (iMLS) erm(A) or erm(C) genes. After overnight incubation in the presence of the non-inducer MLS$_B$ antibiotics, spontaneous mutants constitutively expressed MLS$_B$ resistance were selected. Against our expectation, the mutation ratio of erm(A) was lower than erm(C). Therefore, possibilities of other factors determining the ratio of cMLS phenotype might be concerned. All the mutants showed sequence alterations in translational attenuator and all the alterations seemed to give rise to change the second structure of mRNA to express constitutively. For erm(A), 4 different types of sequence deletions ranging from 72 bp to 122 bp and 3 different types of duplications ranging 24 bp to 93 bp were detected. Also, there were 9 different types of duplications ranging 15bp to 154bp in erm(C).

국민임대주택의 평면구성비 변화에 관한 연구 -전라남도 장성군을 중심으로 - (A Study on the Changes in Spatial Composition Ratio of National Rental Houses - Focused on the Jangseong-gun Jeollanam-do Province -)

  • 김홍배
    • 한국농촌건축학회논문집
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    • 제20권1호
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    • pp.61-68
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    • 2018
  • This study aims to investigate the changes in area ratios by space through floor plans of national leasing houses constructed by the LH in Jangseong-gun, particularly focusing on the floor plans of public leasing housing complexes built during the 1970s-80s and those during the 2010s. The results are as follows: First, according to the composition ratio of floor plans by period, the type of Bedroom> Livingroom> Common Area> Kitchen+Dining> Multi-purpose room> Bathroom> or the type of Bedroom> Livingroom> Kitchen/Dining> Common Area> Bathroom> Multi-purpose room were found to be high during the 1970s. Whereas, the type of Common Area>Living room(Kitchen/Dining included)>Bedroom>Bathroom>Front Entrance was found to be high during the 2010. It can be concluded that the ratio of Bedroom and Living room was found to be high during the 1970s, but after 2010s, the spacial composition ratio of Common Space, Living room, and Bedroom is getting higher in the order. Second, in terms of the composition ratio of floor plans by the area of unit household, among the floor plan of C-1, B-2, B-3, C-2 which were used since 2010s, the spatial ratio of Bedroom was maintained in the range of 20%; while during the 1970s, the Bedroom space of A-1(46%), A-2(46%), and A-3(41%) was found to be higher than 40%. It can be concluded that the size of bedroom space has doubled over time. In terms of the changes in the spatial ratio of Living room, A-1(15%), A-2(22%), and A-3(23%) were found during the 1970s. Compared to the recent floor plans of C-1(28%), B-2(25%), B-3(33%), and C-2(34%) which are applied in Jangseong-gun, Jeollanam-do province, no big changes have been found, particularly in the small floor plans (20% range).

Elastic settlements of identical angular footings in close proximity

  • R. Sarvesha;V. Srinivasan;Anjan Patelb
    • Geomechanics and Engineering
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    • 제32권2호
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    • pp.193-207
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    • 2023
  • In general, the numerous classical approaches available in the literature can anticipate the settlement of shallow foundations. As long as the footings are not in close proximity to other subsurface buildings, the findings achieved using these methods are legitimate and acceptable. However, due to increased urbanisation and land scarcity, footings are frequently built close together. As a result, these footings' settlement behaviour differs from those of isolated footings. A simpler approach for assessing the settlement behaviour of two square or rectangular footings placed in close proximity is presented in this work. A Parametric study has been carried out to examine the interference effect on the settlement of these footings placed in close vicinity on the surface of a homogeneous, isotropic and elastic soil medium. The interaction factors are examined by varying the different aspect ratios (L/B), clear spacing ratio (S/B) and intensity of loading on the right footing with respect to the left footing. Further, variation of the settlement ratio (δ/B) with respect to embedment depth ratio Df/B is examined. For square and rectangular footings, the interference settlement profile is also investigated by varying the clear spacing ratio (S/B) and the degree of loading. The results were compared to 3D finite element analysis and experimental data that were available.

다이버시티를 갖는 고정 무선 중계 시스템에 대한 보호비의 수학적 표현과 계산에 대한 연구 (A Study on A Mathematical Formulation of Protection Ratio and Its Calculation for Fixed Radio Relay System with Diversity)

  • 서경환
    • 한국전자파학회논문지
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    • 제17권4호
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    • pp.358-367
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    • 2006
  • 본 논문에서는 다이버시티 구조를 갖는 고정 무선 중계 시스템의 보호비 계산을 위한 수학적 표현과 계산방법을 제안한다. 공간 또는 주파수 다이버시티를 갖는 시스템의 보호비 계산과 물리적 의미를 분석하며, 특히 다이버시티 개선인자에 관련된 안테나 이득, 안테나 이격거리, 주파수, 캐리어 주파수간 이격, 거리의 변수에 따라 보호비를 고찰한다. 계산 결과의 한 예로 주파수 6.2 GHz, 거리 60 km, 64-QAM, 수직 이격거리 25 m인 공간 다이버시티 시스템의 동일 채널 보호비는 약 60 dB가 되며, 이는 적용하지 않는 경우보다 약 15 dB 적음을 알 수 있었다. 또한 동일한 조건에서 주파수 이격 0.5 GHz인 주파수 다이버시티 시스템의 동일 채널 보호비는 약 64 dB이며, 이는 적용하지 않은 경우에 비해 약 11 dB 적음을 알 수 있었다. 결과적으로 공간 다이버시티시스템이 주파수 다이버시티 시스템보다 간섭에 덜 민감하며, 이는 주어진 간섭에 대해 상대적으로 양호한 품질을 확보할 수 있음을 시사한다.